Carboxylic Acids And Derivatives Flashcards
What is the formula group for a carboxylic acid?
COOH
End in the suffix oic acid
What are the trends in solubility of carboxylic acids?
Carboxylic acids with short alkyl chains are very soluble since they can from hydrogen bonds.
Solubility decreases as the length of the hydrocarbon chain increases since this is a non polar part of the molecule.
What kind of intermolecular forces are present in carboxylic acids?
COOH group has 3 polar bonds meaning they can form hydrogen bonds
They can therefore form dimers ( hydrogen bonding between 2 of the same molecules without the presence of water)
What is the trend in booming point of carboxylic acids?
Have high boiling points due to the hydrogen bonding between the molecules. This means lots of energy is required in order to over come the intermolecular forces.
Explain a carboxylic acids acidity properties
Carboxylic acids are weak acids as they only partially dissociate.
What is the functional group for an Ester?
COO
How is an Ester formed?
Via combining an alcohol with a carboxylic acid
Using a sulphuric acid catalyst and heating gently
(Esterification reaction)
Make larger esters by heating under reflux
They can also be made from alcohols and acid anhydrides (2 carboxylic acids joined together)
What happens during the acid hydrolysis of an Ester?
Can reverse Esterification by using hydrolysis.
Different products are formed depending on the reaction conditions.
Refluxing the Ester in hot aqueous acid will produce a carboxylic acid and an alcohol
What happens during the alkali hydrolysis of an Ester?
Can reflux Ester with hot aqueous alkali to form a carboxylate salt and an alcohol.
Use this process in saponification (making soaps)
What are some uses of esters?
Used in perfumes as they produce pleasant smells
Used to make biodiesel
How is biodiesel produced?
Reacting triglycerides ( from vegetable oils) with methanol using a strong alkaline catalyst forms a mixture of methyl esters which are used as fuel
How does the saponification reaction occur?
Using the alkaline hydrolysis of an Ester to produce a carboxylate salt and an alcohol.
Triglycerides are tri-esters (from vegetable oils)
Triglycerides + 3NaOH ——> glycerol + sodium sterate ( C17H35-COO-Na+)
Sodium sterate is a key component in making soaps and is a salt of a fatty acid
The alcohol produced is used as a sweetener in skin or dental care
What is the functional group of an acyl molecule?
ROCl
What is an acyl chloride?
Derivative of a carboxylic acid where the OH group is replaced by a Cl group.
How are acyl chlorides formed?
Reacting a carboxylic acid with SOCl to form the acyl chloride, sulphur dioxide and HCL.
Separate the acyl chloride his distillation
How do you name acyl chlorides?
Suffix -oyl chloride
Eg methanoyl chloride
Ethanoyl chloride
Propanoyl chloride
How are esters produced using acyl chlorides?
Reacting acyl chloride with alcohols makes esters
High yield than using carboxylic acids
To make aromatic esters you must use phenols and acyl chlorides.
What happens when you react an acyl chloride with:
Water
Ammonia
Primary amines
Secondary amines
Water + acyl chloride = carboxylic acid
Acyl chloride + conc ammonia = primary amide
Acyl chloride + primary amine = N substituted amides
Acyl chloride + secondary amines = N-N amides
What kind of reactions occur when an acyl chloride reacts with
Water
Alcohols
Ammonia
Amines?
Nucleophilic addition elimination reactions
Water
Alcohols
Ammonia
Amines
They all act as nucleophiles
What are the products formed when an acyl chloride reacts with
Water
Alcohols
Ammonia
Amines
In a nucleophilic addition elimination reaction?
Water ——> carboxylic acid
Alcohol ——> ester
Ammonia ——> amide
Amine ——> N substituted amide
What is an amide?
A nitrogen containing compound
Similar to an acyl chloride but the Cl group is replaced by an amine group NH2
What are primary secondary and tertiary amides?
Primary:
1 carbon attached to the nitrogen atom
Secondary:
2 carbon attached to the nitrogen atom
Tertiary:
3 carbon attached to the nitrogen atom
How are amides named?
Using the suffix amide
Eg methanamide
Secondary amides add on an N-alkyl prefix to show the extra alkyl group
Eg N-methylmethanamide
